Fiore is noted especially by his designs of the 1960s, where he mixed text and images, different sizes of type and other unconventional devices to create dynamic pages that reflected the tumultuous spirit of the time. In the words of critic Steven Heller, Fiore was "as anarchic as possible while still working within the constraints of bookmaking".[1]

Of particular interest are his collaborations with media theoristMarshall McLuhan, such as The Medium is the Massage (1967). Initiated by Fiore, the book has been described as the seed from which the idea that "consciousness can be affected by the knowing collision of verbal and visual information" sprouted.[2] The style was pushed further in DO IT!: Scenarios of the Revolution (1970), the controversial yippie manifesto by social activist Jerry Rubin.

In 1968 The Medium is the Massage was made into an LP (Columbia, CS 9501, CL 2701), combining readings of excerpts of the book with musical samples and original musical accompaniments. In 1999, a remastered version was released in CD format by SME Japan.